an assessment of prasugrel on healthy adults and sickle cell adults

Conditions: Anemia, Sickle Cell

Summary: the purpose of this study is to measure the exposure to prasugrel's active metabolite and the pharmacodynamic effects of prasugrel treatment in people with sickle cell disease (scd).


Eligibility criteria:
inclusion criteria: * are 50 to 100 kilograms (kg), inclusive, at the time of screening. * have signed informed consent. * if female, agree to use a reliable method of birth control during the study or are women not of child-bearing potential due to surgical sterilization (hysterectomy or bilateral oophorectomy or tubal ligation) or menopause. * control subjects - are healthy adults as determined by medical history, physical examination, and other screening procedures. * sickle cell disease (scd) subjects - subjects on hydroxyurea must be on a stable dose for the 30 days prior to enrollment without signs of hematologic toxicity at screening. * scd subjects - are adults with scd (hemoglobin ss \[hbss\], hb s beta0 thalassemia, hb sc or hb s beta+ thalassemia genotype) without a diagnosis of acute vaso-occlusive crisis (voc) requiring medical intervention in an emergency department, infusion center, or as an inpatient) within the month prior to screening. exclusion criteria: * have a concomitant medical illness (for example, terminal malignancy) that, in the opinion of the investigator, is associated with reduced survival over the expected treatment period (approximately 1 month). * exhibit severe hepatic dysfunction (cirrhosis, portal hypertension, or alanine aminotransferase \[alt\] for aspartate aminotransaminase \[ast\]≥3 times upper limit of normal \[uln\]). * exhibit severe renal dysfunction defined as cockcroft-gault creatinine clearance\<30 milliliters per minute (ml/min), or requiring chronic dialysis. creatine clearance = \[(140-age) \* mass (in kg)\] \\ \[72 \* serum creatinine (in milligrams per deciliter \[mg/dl\])\]. * exhibit any contraindication for antiplatelet therapy. * have a history of intolerance or allergy to approved thienopyridines. * exhibit any signs or symptoms of an infection. * have a hematocrit \<18%. * exhibit any history of bleeding diathesis, bleeding requiring in-hospital treatment, or papillary necrosis. * have active internal bleeding. * have a history of spontaneous bleeding requiring in-hospital treatment. * have gross hematuria or \>300 red blood cells (rbc)/high-powered field (hpf) on urinalysis at the time of screening. * history of previous intraocular hemorrhage which required treatment with surgery or laser, or evidence of active intraocular haemorrhage. * have a prior history of transient ischemic attack (tia), ischemic stroke, hemorrhagic stroke or other intracranial hemorrhage. * have a known history of intracranial neoplasm, arteriovenous malformation, or aneurysm. * have clinical findings, in the judgment of the investigator, associated with an increased risk of bleeding. * have an international normalized ratio (inr) known to be \>1.5 (inr testing not required for study entry). * have had recent surgery (within 30 days prior to screening) or are scheduled to undergo surgery within the next 60 days. * have a recent history of clinically significant menorrhagia. * have used any aspirin, warfarin, or thienopyridine in the 10 days prior to enrollment. * have used any non-aspirin non-steroidal anti-inflammatory drug (nsaid) in the 3 days prior to enrollment. * anticipate using aspirin, warfarin, nsaid, thienopyridine or other antiplatelet agent during the study period. * are women who are known to be pregnant, who have given birth within the past 90 days, or who are breastfeeding. * regular use of drugs of abuse and/or unacceptable positive findings on urinary drug screening (a positive urinary drug screening for sleep inducers or pain medications in subjects with scd will be considered as an acceptable finding). * are currently enrolled in, or discontinued within the last 30 days from, a clinical trial involving an investigational drug or device or off-label use of a drug or device, or are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study.